Means for energizing radio apparatus



MEANS FOR ENERGIZING RADIO'APPARATUS Filed Sept. 7, 1928 2 Sheets-Sheet1 INVENTOR (ORNEUS 50L BY tomzus HJMOREL .AT RNEY Nv. 12, i929.

c. BOL ET AL MEANS FOR ENERGIZING RADIO APPARATUS Filed Sept. '7. 1928 2Sheets-Sheet 2 INVENTOR commas BOL coaueus MOREL 9w Jaum TORNEY PatentedNov. 12, 1929 UNITED STATES PATENT OFFICE I I CORNELIS BOL AND CORNELISHENDRIX MOREL, OF EINDHOVEN, NETHERLANDS, AS-

SIGNORS T0 RADIO CORPORATION OF AMERICA, A CORPORATION OF DELAWARE MEANSFOR ENERGIZING RADIO APPARATUS Application filed September 7, 1928,Serial Noam 1,542, and in the Netherlands September 3, 1927.

An application for this invention has been filed in the Netherlands,September 3, 1927.

This invention relates to wireless receiving sets and has for itspurpose to so construct them that they can be easily adapted, at will,for continuous current or for alternating current feeding of theincandescent cathodes of the discharge tubes.

According to the invention, for this purpose the set has mounted on orin it a row of contacts some of which are connected to supply leads ofthe sources of current while other ones are connected to points of thecircuit-arrangement proper which have to be fed by the said sources.Optionally, these contacts may be mutually connected in groups by strapsor again they may be connected to corresponding contacts of a small boxarranged or adapted to be arranged within or against the set andcontaining a transformer, a rectifier with smoothing device and a potentiometer, the arrangement being such that in the first mentioned casethe set is adapted for continuous current feeding and in the second casefor alternating current feeding, in which latter case the requirednegative potentials may be derived from the potentiometer.

According to the invention, in the second case the box supplying thenegative potentials when alternating current is used is given about thesame dimensions as those of the grid biasing battery which must be usedwhen the filaments are fed by continuous current.

The invention will be more clearly understood by referring to theaccompanying drawings which represent, by way of example, an embodimentof the invention. In the drawings- Figure 1 shows a diagram ofconnections of a set according to the invention.

Figures 2 and 3 are views of a set according to the invention, in whichonly those parts are shown which are essential for the rightcomprehension of the invention.

In Figure 1, the parts belonging to the re ceiving set proper areseparated by a dotted line from the auxiliary apparatus which is adaptedto supply the heating current and the negative bias from an alternatingcurrent mains, the first-mentioned parts being indicated by O and thelatter parts byW.

The various parts of the receiving set, which are indicated in thediagram in the usual manner, will not be described in detail. Thedifferent points of the circuit-arrange- I ment 'which have to beconnected to the sources of current, are connectedto contacts 2, 3, 4-,5, 7, 8, 11 and 13. In thecase of continuous current feeding of the set,a dry or other battery V for the supply of the required negative biasmay be mounted between terminals 14 and 15.

Bymeans of external leads for continuous current feeding the terminals 1and9 are connected respectively to the positive and negative poles ofastorage-battery B, the terminal 12 being earthed.

With continued current feeding,there are provided three straps B B Bwhich respectively establish the mutual connection of theterminalsl, 2,3, the terminals 4, 5, 6 and the terminals 9, 10 and 11. As will beobviou's by an inspection of the drawings estab lishing the aboveconnections will complete circuits to energize the filament of tubes 40,41, and 42 as follows: The filament ofthe tube 40 will be connected inparallel with the battery B through circuit A+, 1, 2, r, the

filament of 40, 4, 6, 1 0, 9and A. Thefilament of 41 is put directly inparallel with B through the circuit A+, 1, 3, the filament of a 41, 5,6,10 and A-, while the filament of 42 is connected in parallel with Bthrough A+2,

the filament of 42, 11, 9 and A. The purpose of resitsance'r is to applythe correct voltageto the filament ofradio frequency amplifier 40. Theproper grid biasing potentials for the detector 41 is obtained byconnecting the grid of 41 to the movable contact of potentiometer Pconnected across the filament heating circuit. If one wants to feed theset exclusively with alternating current, the three straps B B B areremoved and the terminals 1-9 and also the terminal 14 of the set areconnected to terminals 1 to 9 inclusive and 35 respectively of theapparatus WV which last mentionedterminals are shown in the drawingsopposite to the which are connected to the terminals 1 and 9 areconnected directly to terminals 1 and 9 of the mains leading to thealternating current source at the left of Figure 1, instead of beingconnected to the storage-battery B. This connection puts the primarywinding 20 of a transformer in parallel with the alternating currentsource. This transformer has three secondary windings 21, 22 and 23. Thewinding 21 supplies current to a circuit which comprises a rectifier 24,smoothing condensers 29, 30, 31 and 32 and imp-edances in the form ofohmic resistances 25, 26, 27 and 28. A lead connects the end of theresistances 28 to a terminal 33 which is connected to the terminal 1%,in which case the dry battery V for the supply of the grid bias can bedispensed with.

The transformer winding 22 which is provided with a middle-branching,supplies the heating current to the cathode of the rectifier 2e and tothe cathodes of the high-frequency valve and the final valve of thereceiving set. The transformer winding 23 furnishes the heating currentfor the detector which, in contradis'tinction to the two other valves,is indirectly heated and which therefore must be fed as a rule withanother tension.

Figures 2 and 3 show two views of the same. set, in Figure 2 alternatingcurrent feeding and in Figure 3 continuous current feeding beingutilized. 7

Of this set the drawing only represents a high-frequency valve 40, adetector-valve 421 and a final'valve 42 and, in addition, a lowfrequencytransformer 43 and in the one case the apparatus TV with theconnection-contacts and in the other case the grid biasing battery V.

As shown in Figure 2 the various contacts 1, 2, 3, etc. of the receivingset are connected for the greater part to opposite cont cts of theapparatus W whereas in Figure 3 the various contacts of the set areconnected, in groups, by the three straps B B B The apparatus WV isgiven such a shape that, inclusive of the rectifying valve G, it hassubstantially the same dimensions as the grid biasing battery V andconsequently can easily be mounted instead of the latter.

lVhat we claim is:

1. In radio apparatus to be used with radio receivers having thermionictubes and filaments therein adapted to be energized by direct current orby alternating current, a plurality of contacts each associated with oneor more "of the electrodes to be heated, means for connecting togethergroups of said contacts when applying direct current to said electrodes,means for supplying biasing voltages to the control electrodes of saidtubes when the filaments thereof are energized by direct currentcomprising a separate source of po tential, means for connecting analternating current source to the filaments of said tubes when thedirect current source is disconnected therefrom and means for supplyingbiasing potentials to the control electrodes of said tubes when thefilaments thereof are energized by alternating current comprising arectifier adapted to be fed by alternating current.

2. The combination of a radio receiver including thermionic tubes,direct current sources therefor including a separate grid biasingsource, an alternating current source therefor, means for connectingeither of said sources in parallel with the filaments of said tubes andmeans adapted to replace said separate grid biasing source when thealternating current source is connected to said receiver, comprising arectifier energized from an alternating current source.

3. The combination of a radio receiver, including thermionic tubes,direct current sources therefor including a separate grid biasingsource, an alternating current source therefor, means for connectingeither of said sources to the filaments of said tubes and means toprovide a grid bias'p'otential for the grids of said tubes whenthealternating current source is connected to the receiver, comprising athermionic rectifier energized from an alternating current source.

CORNELIS BOL. CORNELIS HENDRIK MOE-EL.

